Liquid flow diffusion and straightening apparatus

ABSTRACT

Liquid flow diffusion and straightening apparatus, especially useful to provide an even velocity profile for water entering the pump of a circulation system. A cylindrical housing has a crosssectional plane of symmetry on which the flow inlet and outlet are located, there being an interior chamber leading to the outlet. The inflowing water is divided into halves which flow away from the plane of symmetry and are slowed within the housing ends. The flows then enter the interior chamber through the ends of cylindrical diffusion screens, pass therethrough, and are rejoined inwardly of the flow outlet.

United States Patent 1 91 Blackmore et al.

[ LIQUID FLOW DIFFUSION AND STRAIGHTENING APPARATUS [76] Inventors: Joseph J. Blackmore, R.R. No. l

Edwardsville, Ill. 62025; Perry G. Glunt, 91 Wildwood Lane, Kirkwood, Mo. 63122 i [22] Filed: Nov. 17, 1971 [21] Appl. No.: 199,416

52 us. Cl ..138/41, 210/323 51 1m. 01 ..F16l FlSd [58] Field of Search ..l38/4l, 37,39,40,

[56] References Cited UNITED STATES PATENTS Blackmore etal. ..l38/4l Allen ..417/92 1451 Apr. 17,1973

Primary Examiner.loseph R. Leclair Assistant Examiner-Steven M. Pollard Attorney-Jerome A. Gross 5 7 ABSTRACT Liquid flow diffusion and straightening apparatus, especially useful to provide an even velocity profile for water entering the pump of a circulation system. A cylindrical housing has a cross-sectional plane of symmetry on which the flow inlet and outlet are located, there being an interior chamber leading to the outlet. The inflowing water is divided into halves which flow away from the plane of symmetry and are slowed within the housing ends. The flows then enter the in terior chamber through the ends of cylindricaldiff usion screens, pass therethrough, and are rejoined inwardly of the flow outlet.

8 Claims, 5 Drawing Figures PATENTEDAPRI 11913 7 51727. 643

' sum 1 or 3 JOSEPH J. BLAC KMORE l v INVENTORS ATTORNEY PAIENT APR 1 mm sum 2 or 3 FIG. 4

INVENTORS JOSEPH J. BLACKMORE PER Y C. GLUNT ATTORNEY PATENTEUAPR 1 H975 sum 3 [1F 3 INVENTORS JOSEPH J. BLACKMORE PERRY G. 'GLUNT ATTORNEY LIQUID FLOW DIFFUSION AND STRAIGHTENING APPARATUS BACKGROUND OF THE INVENTION This invention relates to flow diffusion and straightening apparatus, as employed in pumped liquid systems such as hot water circulating systems; and it is particularly useful for straightening and diffusing the flow of water into the suction side of the pump.

Liquid flowing through a pipe having a straight section of ample length and inside diameter may have a fairly regular velocity profile. Such an ideal condition is seldom realized. For example, a return flow line typically has a 90 pipe bend immediately in advance of a pump; this so affects the flow to the pump as to be like- .ly to cause cavitation. Further, where the pump is of a type which divides the flow into two parts, it is ofa special importance that the liquid inflow have a substantially symmetrical flow profile; otherwise the amounts of liquid delivered to the two sides of the pump will be unequal.

One type of apparatus, useful for the present purpose but of limited flow capacity, is shown in our US. Pat. No. 3,266,437 entitled Flow Director and Strainer."

SUMMARY OF THE INVENTION The present flow. diffusion and straightening apparatus utilizes a relatively elongated housing having a cross-sectional plane of symmetry, on which its flow inlet and flow outlet are located. An interior chamber, which leads to the flow outlet, has a wall which serves as means to divide the flow from the inlet into substantially equal halves and direct them to opposite ends of the housing. The flow capacity within these ends is greater than that of the inlet, thereby slowing the flow.

Within the interior chamber are diffuser means, preferably elongated cylindrical screens arranged perpendicular to the cross-sectional plane of symmetry. The flow from the housing ends passes inward, through the ends of the screens, and through the screen perforations in a diffused, relatively slow flow. The flow to the outlet re-forms equally from both sides of the plane of symmetry, and exits through the flow outlet in a profile which is symmetrical relative to the plane of symmetry. Such a flow profile is substantially ideal for introduction into a suction pump.

DESCRIPTION or THE DRAWINGS FIG. 1 is a front elevational view of a flow diffusion and straightening apparatus embodying the present invention.

FIG. 2 is a top view thereof, the left side of which is broken away.

FIG. 3 is an elevational view thereof from the side opposite FIG. 1, partly broken away and showing portions thereofin exploded position.

. FIG. 4 is a sectional view'taken along line 44 of FIG. 3.

FIG. 5 is a perspective view of the diffuser assembly incorporated in the apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENT The flow diffusion and straightening apparatus illustrated in the drawings includes a housing generally designated 10, shown in FIGS. 1, 2, 3 and 4. It has a substantially cylindrical hollow body 11 formed about a lateral axis 12 which extends transversely perpendicular to a vertical cross-sectional plane of substantial symmetry 13. The housing is preferably of welded steel construction. It may be supported from beneath by a longitudinal channel 15 having a central support leg 16.

At the plane of symmetry 13 are a short tubular flow inlet and a flow outlet 21, each having an external attachment flange 22 for bolted connection within the liquid flow system. For example, the flow inlet 20 may be connected to the return line of a water circulation system, and the flow outlet 21 connected to the inlet of a circulation pump. The axes of the flow inlet and outlet 20, 21 are preferably perpendicular to the axis 12 of the body. Instead of being spaced angularly at 90 to each other, as shown in the drawings of this embodiment, they may be spaced angularly from each other at some other convenient angle; for example, in a horizontal flow line the inlet 20 would be at 180 from the outlet 21. Preferably the outlet 21 is equipped with straightening vanes, such as the horizontal vane 23 and vertical vane 24 shown in FIGS. 1 and 4, wherein the vertical vane 24 is in the vertical plane of symmetry 13 and the horizontal vane 23 is in a plane defined by the axis 12 of the body 11 and an axis 25 of the flow outlet 21.

Referring to FIG. 3, the housing 10 includesa fixed rounded end 27, welded in place. At the opposite side of the plane of symmetry 13, the cylindrical wall 11 has an inwardly curved mounting flange 28 having a vertical end surface 29 faced to receive a mating flange por' tion '30 of an end cap 31. A circumferential seal 32 is provided within the mating flange portion 30. Bolted provisions are made, as shown, to secure the cap 31 removably to the mounting flange 28.

The mounting flange 28 provides, along the axis 12, a narrow inner cylindrical surface 34 which receives the outer edge 35 ofa dished plate baffle 36 mounted on a central tubular spacer 37. When mounted as shown in dashed lines in FIG. 1 with the tubular spacer 37 aligned with the axis 12, the baffle 36 is so positioned as to provide a liquid flow space within the housing 10.

substantially symmetrical to that'provided at the opposite end by the concave inner surface of the rounded housing end 27.

At the juncture of the end 27 with the bottom portion of the body 11, a conventional tubular clean-out drain 39 is provided, normally closed by a screw plug 40 as shown in FIG. 1.

Within the housing 1 0 is provided an interior chamber to be described, which leads to the flow outlet 21 and serves to separate the flow inlet 20 therefrom. Such an interior chamber is made up of a U-shaped wall generally designated 42, best shown in the crosssectional view FIG. 4. Its U-shape is tilted at so that its open portion is directed toward the flow outlet 21. The U-shaped wall 42 is longer than the diameter of the flow outlet 21 and shorter than the cylindrical housing body 11. It extends symmetrically to both sides of the plane of symmetry 13. The U-shaped wall 42 includes upper and lower opposed flat wall portions 43, 44 leading inward from the cylindrical surface immediately above and below the flow outlet 21. Where they reach the center of the housing, viewed from above as in FIG. 2, they merge into a curved wall portion 45 which is rounded about the transverse axis 12, so that it faces toward the outlet 21.

At the lateral ends of the wall 42, joining at least the flat upper and lower wall portions 43, 44 thereof, are a pair of interior divider walls 47 best shown in FIG. 4. They are joined to that side of the body 11 in which the flow outlet 21 is located, and extend inward. As seen in FIG. 4, each divider wall 47 has a circular inner edge 48 whose radius is somewhat smaller than that of the curved wall portion 45, the inner edge 48 defining aa large opening along the transverse axis 12 into themterior of the chamber so provided.

The spacing of the interior divider walls inward from the fixed end 27 and baffle 36 (which serves for flow purposes as the opposite housing end) is such as to provide spaces for flow within said ends whose total crosssection exceeds that of the flow inlet or flow outlet 21. A horizontal vane 49 welded at the midlevel of the curved wall portion 45, extends aft from it to fit close against the inner surface of the body 10. Hence flow from the inlet 20 will descend downwardly toward the U-shaped wall 42, and the horizontal fin 49, and will be divided in substantially equal halves to flow away from the plane of symmetry into these end spaces.

Within the interior chamber, whose inlets are the circular openings 48 in the divider walls 47, perforate diffuser means generally designated 50 are supported. A diffuser assembly is shown in FIG. 5. It includes disclike carrier end plates generally designated 51 whose circular outer edges 52 fit slidably within the circular V inner edges 48 of the divider walls 47; and this fit may provide support for the diffuser means 50. The end plates 51 have axial bores 53 and four large circular, inwardly counterbored or flanged openings 54, spaced in a circular pattern. The end plates 51 are drilled between the openings 54 to receive tie rods 55 having threaded ends and nuts, as shown, to hold the openings 54 in alignment. The openings 54 thus provide end mounts and parallel axes of support for four tubular diffusing screens 58, which'may be perforated metal cylinderswhose perforations exceed, in total area, the crosssectional area of the flow outlet 21.

Instead of the diffuser assembly 50, a single cylindrical screen might be fitted to extend between the openings 48 of the divider walls 47. The four-screen assembly of FIG. 5 has the advantage of greater surface area, minimizing the attendant pressure drop and turbulence as the flow halves rejoin within the interior chamber.

To position the diffuser assembly 50 so described within the interior chamber of the housing 10, a vertical strut 60 having a central bore 61 is welded across the chambers inner edge 48 near the fixed end 27 of the housing 10. Above and below its central bore 61 the strut 60 has relief openings 62 to accommodate the ends of the tie rods 55, as seen in FIG. 3. When the assembly 50 is positioned with its end plates 51 within the wall openings 48, the vertical strut 60 serves as a positioning abutment for the adjacent end plate 51.

For convenience in inserting and removing the diffuser means 50, a central rod 64 is utilized, whose length is such as to fit within the overall inner length of the housing 10, as best seen in FIG. 1. Within the diffuser assembly 50 is a tubular spacer 65, which may serve as a part of the diffuser assembly to space apart the plates 51', it mounts slidably on the rod 64. When the rod 64 is in place as shown in FIG. 1, it passes through a central bore 61 of the vertical strut 60. The tubular spacer 37 which positions the diffuser assembly 50 and mounts the baffle 36 fits slida ly on the rod 64 at the side of the diffuser assembly 0 opposite to the strut 60, as seen in FIG. 3. Hence when the cap 31 is removed the baffle 36 may be slid horizontally along and off the end of the rod 64, to be removed through the housing end opening 34. The rod 64 may then be used to support the diffuser assembly 50 as it is drawn horizontally outward through the opening 34. This permits easy cleaning and replacement of the diffusing screens 58.

In use, liquid flow from the inlet 20 of the outlet 21 is divided substantially evenly into two parts as shown by the arrows in FIG. 1; and these parts flow to the spaces within the opposite ends of the housing 10. The relatively large spacing of the divider walls 47 inwardly of the end 27 and the baffle 36 provides flow passages of greater capacity than the cross-sectional flow area within the inlet 20 or the outlet 21; this serves to slow the flow within the ends. From them, the liquid flows and the U-shaped wall 42 are disposed symmetrically.

relative to the horizontal plane defined by the lateral axis 12 and the flow outlet 21. They direct the flow as to rejoin inwardly of the flow outlet 21 in a flow profile which is substantially symmetrical relative to the horizontal and vertical planes of symmetry. This symmetry is shown by the outlet arrows in FIGS. 2 and 4.

As the diffused flow is rejoined at the vertical plane of symmetry 13 inwardly of the flow outlet 21 its flow profile is smooth. Normally it will be substantially constant over the entire area of the flow outlet 21; and the straightening vanes 23, 24 are precautionary. If the diffuser apparatus is not appropriately sized for the rate of flow, as for example if of larger capacity than necessary, the flow profile, as shown in FIGS. 2 and 4, may depart from a straight line, but will always be substantially symmetrical.

In those installations where theliquid flows vertically downward immediately before reaching the pump, use of the embodiment illustrated, with its inlet 20 extending vertically downward at the plane of symmetry and its outlet 21 extending horizontally, serves to relieve the uneven flow condition which a elbow in a flow pipe would create.

Inasmuch as the housing 10 is completely filled with liquid at all times during operation, it may be installed with the inlet 20 and outlet 21 at any angle. The description and illustration of the vertical inlet 20 and horizontal outlet 21 are therefore merely exemplary.

When using a suction pump of the type which divides the flow into two parts, even in horizontal flow lines,

the regular symmetrical flow profile of the present invention is highly desirable. For such use, the housing of the apparatus may be modified to have its flow inlet at 180 from its flow outlet, and the horizontal fin 49 would be dispensed with. Other modifications will suggest themselves for varying uses.

We claim:

1. For use in liquid flow systems to produce symmetrical velocity distribution,

flow diffusion and straightening apparatus comprisa housing including a substantially cylindrical body formed about an axis and having a cross-sectional plane of substantial symmetry, to which the axis is transverse a flow inlet and a flow outlet at said plane of symmetry, the flow outlet being perpendicular to the axis of the body, the housing further having housing ends closing said cylindrical body, and

an interior chamber leading to the flow outlet and separating the flow inlet therefrom, said interior chamber comprising a U-shaped wall shorter than the housing and positioned therein symmetrically to extend to both sides of the plane of symmetry, said U-shaped wall including two opposed wall portions leading to the outlet and spaced from each other substantially the diameter of the outlet and connected by a wall portion curved about said transverse axis and op posite to and facing the outlet, the chamber further having interior divider walls at the ends of said ,Ushaped wall and joined to and extending inwardly from that side of the cylinder wall in which the flow outlet is located,

each divider wall having an inner edge defining, at least in part, an opening along the transverse axis into said interior chamber,

perforate diffuser means having lateral end openings,

and

means at the divider wall openings to receive the end openings of the diffuser means, and to position the diffuser meansspaced inwardly from the U-shaped wall,

whereby liquid flow from the inlet to the outlet is divided substantially evenly into two parts and delivered bythe U-shaped wall to flow toward the housing ends prior to entering the diffuser means and flowing back to the flow outlet. 7

2. Flow diffusion and straightening apparatus as defined in claim 1, wherein the flow inlet is perpendicular to a plane defined by the said transverse axis of the cylindrical body and the axis of the flow outlet, and

the spacing of the interior divider walls inward from the housing ends is such as to provide a greater cross-section for flow within said ends than at the flow inlet or flow outlet,

whereby to slow the flow within said ends prior to flowing back through the diffuser means to the flow outlet.

'3. Flow diffusion and straightening apparatus as defined in claim 1, wherein the perforate diffuser means comprises a plurality of perforate cylinders, and

the means to support said diffuser means includes a carrier end plate having means to define parallel axes of support for the perforate cylinders.

4. Flow diffusion and straightening apparatus as 5 defined in claim 1, wherein one end of the housing is a rounded fixed end, and the other end of the housing is removable, whereby to permit removal of the diffuser, and an inner rounded removable end member is provided at the removal housing end, whereby to provide in ternal symmetry with the rounded fixed end. 5. Flow diffusion and straightening apparatus as defined in claim 1, together with straightening vanes at the flow outlet, said vanes in cluding a first vane member in the plane of symmetry and a second vane member in a plane defined by the axis of the cylindrical body and the axis of the outlet. 6. For use in liquid flow systems to produce symmetrical velocity distribution,

flow diffusion and straightening apparatus comprismg an elongated housing formed about an axis and ineluding opposed housing ends, the housing having a cross-sectional plane of substantial symmetry,

and having a flow inlet and a flow outlet spaced angularly from each other at said plane of symmetry, and

means within the housing to divide the flow from the inlet into substantially equal halves and to direct said halves away from the plane of symmetry toward the opposed ends of the housing there to slow the flow, together with diffuser means to rejoin the flow from the opposed housing ends and lead it to the flow outlet at the plane of symmetry,

whereby liquid flow from the inlet, after being so divided, is rejoined at the flow outlet in a substantially symmetrical flow profile.

7. Flow diffuser and straightening apparatus as defined in claim 6, wherein the diffuser means is positioned along the housing inward ofthe housing ends,

whereby to provide slowed flow in the spacings inward of said housing ends and an increased rate of flow inwardly into said diffuser inlet ends,

said diffuser ends having inlet areas so restricted, relative to the spacings in which such slowed flow occurs, as to provide equal metered flow into each said diffuser end.

8, For use in liquid flow systems to produce symmet-' sured perpendicular to said plane, which exceeds its internal width, a flow inlet at said plane of symmetry, means within the housing to divide the flow into substan tially equal halves and to direct such halves of the flow away from the plane of symmetry opposite to each other toward the interior of the ends of the housing and to slow their velocity,

axis and has diffuser inlet ends positioned spacedly means to communicate such flows therefrom diffusedly back toward the plane of symmetry, and a flow outlet from the housing at said plane of symmetry. 

1. For use in liquid flow systems to produce symmetrical velocity distribution, flow diffusion and straightening apparatus comprising a housing including a substantially cylindrical body formed about an axis and having a cross-sectional plane of substantial symmetry, to which the axis is transverse, a flow inlet and a flow outlet at said plane of symmetry, the flow outlet being perpendicular to the axis of the body, the housing further having housing ends closing said cylindrical body, and an interior chamber leading to the flow outlet and separating the flow inlet therefrom, said interior chamber comprising a U-shaped wall shorter than the housing and positioned therein symmetrically to extend to both sides of the plane of symmetry, said U-shaped wall including two opposed wall portions leading to the outlet and spaced from each other substantially the diameter of the outlet and connected by a wall portion curved about said transverse axis and opposite to and facing the outlet, the chamber further having interior divider walls at the ends of said U-shaped wall and joined to and extending inwardly from that side of the cylinder wall in which the flow outlet is located, each divider wall having an inner edge defining, at least in part, an opening along the transverse axis into said interior chamber, Perforate diffuser means having lateral end openings, and means at the divider wall openings to receive the end openings of the diffuser means, and to position the diffuser means spaced inwardly from the U-shaped wall, whereby liquid flow from the inlet to the outlet is divided substantially evenly into two parts and delivered by the Ushaped wall to flow toward the housing ends prior to entering the diffuser means and flowing back to the flow outlet.
 2. Flow diffusion and straightening apparatus as defined in claim 1, wherein the flow inlet is perpendicular to a plane defined by the said transverse axis of the cylindrical body and the axis of the flow outlet, and the spacing of the interior divider walls inward from the housing ends is such as to provide a greater cross-section for flow within said ends than at the flow inlet or flow outlet, whereby to slow the flow within said ends prior to flowing back through the diffuser means to the flow outlet.
 3. Flow diffusion and straightening apparatus as defined in claim 1, wherein the perforate diffuser means comprises a plurality of perforate cylinders, and the means to support said diffuser means includes a carrier end plate having means to define parallel axes of support for the perforate cylinders.
 4. Flow diffusion and straightening apparatus as defined in claim 1, wherein one end of the housing is a rounded fixed end, and the other end of the housing is removable, whereby to permit removal of the diffuser, and an inner rounded removable end member is provided at the removal housing end, whereby to provide internal symmetry with the rounded fixed end.
 5. Flow diffusion and straightening apparatus as defined in claim 1, together with straightening vanes at the flow outlet, said vanes including a first vane member in the plane of symmetry and a second vane member in a plane defined by the axis of the cylindrical body and the axis of the outlet.
 6. For use in liquid flow systems to produce symmetrical velocity distribution, flow diffusion and straightening apparatus comprising an elongated housing formed about an axis and including opposed housing ends, the housing having a cross-sectional plane of substantial symmetry, and having a flow inlet and a flow outlet spaced angularly from each other at said plane of symmetry, and means within the housing to divide the flow from the inlet into substantially equal halves and to direct said halves away from the plane of symmetry toward the opposed ends of the housing there to slow the flow, together with diffuser means to rejoin the flow from the opposed housing ends and lead it to the flow outlet at the plane of symmetry, whereby liquid flow from the inlet, after being so divided, is rejoined at the flow outlet in a substantially symmetrical flow profile.
 7. Flow diffuser and straightening apparatus as defined in claim 6, wherein the diffuser means is positioned along the housing axis and has diffuser inlet ends positioned spacedly inward of the housing ends, whereby to provide slowed flow in the spacings inward of said housing ends and an increased rate of flow inwardly into said diffuser inlet ends, said diffuser ends having inlet areas so restricted, relative to the spacings in which such slowed flow occurs, as to provide equal metered flow into each said diffuser end.
 8. For use in liquid flow systems to produce symmetrical velocity distribution, flow diffusion and straightening apparatus comprising a housing having a cross-sectional plane of substantial symmetry and having an internal length, measured perpendicular to said plane, which exceeds its internal width, a flow inlet at said plane of symmetry, means within the housing to divide the flow into substantially equal halves and to direct such halves of the flow away from the plane of symmetry opposite to each other toward the interior of the ends of the housing and to slow thEir velocity, means to communicate such flows therefrom diffusedly back toward the plane of symmetry, and a flow outlet from the housing at said plane of symmetry. 